So I'll preface this with, it's been a long time since I opened up the hood of the car. And it's been over a year since a mechanic did either. This is a 2012 C. I went in to change the engine air filter, which went fine. But when I went to close the hood I saw this fabric/cotton whatever up in the top-right? Any idea if this belongs there, or fell off or something, or what's going on? I don't have any photos of the engine of my specific Prius. I checked around online before posting this and I don't see anything indicating this should be there.
That's an animal that built a nest in your engine compartment. It's important to regularly inspect and clean your car, especially engine compartment. If nesting goes on for too long you could have your wires chewed through and that's not a cheap repair.
Ok, hah. I was leaning between either animal nest or the last tech left something inside the engine. I was pretty sure it wasn't something unraveling that was protected but wanted to be sure. Yeah I agree I need to check it more.
I agree with @PriusCamper. The plant/soy coated plastics in the engine can easily attract rodents. I found a nest in pretty much the same spot when I was camping last spring. It happened overnight.
Almost certainly a rodent, as already mentioned. Friendly advice section: A year without lifting the hood? That's begging for trouble. You can't assume that you have enough oil, brake fluid, washer fluid, etc. I'd urge you to check that stuff at least once a month if not at every tank. With a 10-year old car, something's going to bite you one of these days if you don't keep an eye on it. Dentists say to only floss the teeth you want to keep. I revise that to recommend only checking the oil on engines you want to keep.
